1. Technical Field
The field relates power take off from hybrid electric vehicles and more particularly to use of the vehicle's powertrain control system to control engagement and disengagement of the power take off.
2. Description of the Technical Field
Some hybrid electric vehicles transmit mechanical torque and angular velocity to a power take off (PTO) output shaft through a use a manual or automated manual type transmission. In these circumstances the PTO conventionally includes an intermediary coupling and decoupling mechanism (hereafter PTO coupler) between the transmission and the loads attached to a PTO output shaft. A problem can occur during either the initial engagement or re-engagement of the intermediary mechanism if the transmission's internal drive gearing is not fully stopped. Engagement combined with the inertia cost down of the traction motor/generator and transmission gearing can create a condition within the intermediary mechanism where coupling gears and shift collar teeth clash due to a difference in speeds (angular velocities) of the two active members. This produces gear grinding problems.